Many oil well facilities around the world operate under high pressure. In other words, the pressure within the well is sufficiently high (e.g., 3000 to 5000 psi) to carry the crude oil to the surface without pumping. Unless restricted, the crude oil flows to the surface at a high velocity and contains sand and other debris which erodes the interior surfaces of the oil well piping components. In order to limit the amount of sand and debris that is carried with the extracted oil, the high well pressure is maintained in the exit piping by using a pressure reducer at the head end of the well. For instance, a six inch inner diameter well pipe is reduced to three inches through a series of harrow channel pipe components. The flow channel is then further reduced to less than one inch, or even less than one-half inch, in the pressure reducer assembly.
The known pressure reducing devices are made of carbon steel and have tungsten carbide inserts to line the inside surfaces of the flow channels. The abrasive oil-and-sand mixture not only wears away the inside wall of the flow channels, but also backwashes around the outside diameter of the flow reducer and wears away the steel body of the flow reducer, resulting in gross failure of the reducer itself. Often, the metal housing surrounding the flow reducer is severely worn as well. Continuous erosion of the pressure reducer over time results in a slow and continuous loss of desired operating pressure until gross failure requires replacement. This loss in operating pressure causes an ever-increasing sand content, resulting in less efficient oil production. Eventually, the oil line must be shut off, and the entire pressure reducer device must be disconnected from the line and replaced.
The average life of known flow reducers is about 4 to 12 weeks. Oil well downtime to replace a pressure reducer and/or other components, is usually four to eight hours. Since high pressure oil wells typically produce about 5,000 to 12,000 barrels of oil a day, the downtime associated with replacement of a pressure reducer can result in a significant loss of oil production. It is readily apparent that the present construction of oil well pressure reducing assemblies leaves something to be desired with respect to wear resistance and useful life.